1. Field of the Invention
The present invention relates to a sensing apparatus and method, and a program therefor, and more particularly to a sensing apparatus and method, and a program therefor that are capable of sensing contact/non-contact of a human body at high speeds and with high accuracy.
2. Description of the Related Art
A touch sensor is generally spreading which senses contact or non-contact of a human body based on a change in capacitance of an electrode and the like.
The touch sensor senses contact or non-contact of a human body by detecting capacitance of an electrode section that provides a contact portion and determining whether the detected capacitance is that of the human body. The touch sensor has been used in, for example, an elevator operation button or a ball launcher of a pachinko game machine.
However, the touch sensor may sometimes operate erroneously when touched by something other than a human being. To solve this problem, a method has been proposed to prevent the touch sensor from operating erroneously.
For example, if a touch key including an electrode is held down for more than a predetermined period of time or if an average value of output variations is not larger than a ratio at the time of maximum variation, a proposed constitution determines that it is not a key operation performed by a human with his/her finger and in such a case, cancels the receiving operation (see, e.g., Japanese Patent Application Laid-Open No. 2007-141541).
According to another proposal, a plurality of sensing electrodes are disposed around a main sensing element of a non-contact type switch, whereby when a signal occurs which senses contact of a human body on the main sensing electrode and when detection signals corresponding to the peripheral electrodes are also generated within a predetermined period of time after the moment of the occurrence, no output signal is generated (see Japanese Patent Application Laid-Open No. 06-162888).
However, in the case of the approach of Japanese Patent Application Laid-Open No. 2007-141541, the output signal may occur if a plurality of switches are pressed by the palm of a hand or if metal approaches the apparatus temporarily.
On the other hand, in the case of the approach of Japanese Patent Application Laid-Open No. 06-162888, a predetermined period of time must be awaited to pass after contact or non-contact of the main sensing element is detected, so that the response speed may be affected.